Planning Activity > Stored Backup Images > Duplicate Copies report
The axis on the left is for the height of the blue bars for example that tells the number of duplicate backup copies that exist overall. The yellow line for example is the axis on the right and it shows the percentage of backup images that are copies. This is a particularly useful report for situations where you want to make certain there is always more than 1 backup copy. If two copies of a backup exist, the blue bar would be a height of 1 (since there is 1 extra copy) and the line would show .5 for 50% since half of the backup images are copies. The same situation for 3 copies would be a blue bar height of 2 and a yellow line percentage of .66 or 66%. In operational use you can filter this report down to specific policies or the clients that you want to ensure always have a 50% or greater yellow line so that more than 1 backup copy exists.